| Name |
| |
| ANGLE_platform_angle |
| |
| Name Strings |
| |
| EGL_ANGLE_platform_angle |
| |
| Contributors |
| |
| Scott Graham, Google |
| Shannon Woods, Google |
| Geoff Lang, Google |
| |
| Contacts |
| |
| Scott Graham, Google (scottmg 'at' google 'dot' com) |
| |
| Status |
| |
| Draft |
| |
| Version |
| |
| Version 5, 2017-12-28 |
| |
| Number |
| |
| EGL Extension XXX |
| |
| Extension Type |
| |
| EGL client extension |
| |
| Dependencies |
| |
| Requires EGL_EXT_client_extensions to query its existence without |
| a display. |
| |
| Requires EGL_EXT_platform_base. |
| |
| This extension is written against the wording of version 9 of the |
| EGL_EXT_platform_base specification. |
| |
| ANGLE_platform_angle_d3d affects the definition of this extension. |
| ANGLE_platform_angle_opengl affects the definition of this extension. |
| |
| Overview |
| |
| This extension defines how to create EGL resources from native resources |
| using the functions defined by EGL_EXT_platform_base. |
| |
| New Types |
| |
| None |
| |
| New Procedures and Functions |
| |
| None |
| |
| New Tokens |
| |
| Accepted as the <platform> argument of eglGetPlatformDisplayEXT: |
| |
| EGL_PLATFORM_ANGLE_ANGLE 0x3202 |
| |
| Accepted as an attribute name in the <attrib_list> argument of |
| eglGetPlatformDisplayEXT: |
| |
| EGL_PLATFORM_ANGLE_TYPE_ANGLE 0x3203 |
| EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE 0x3204 |
| EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE 0x3205 |
| EGL_PLATFORM_ANGLE_DEBUG_LAYERS_ENABLED 0x3451 |
| EGL_PLATFORM_ANGLE_NATIVE_PLATFORM_TYPE_ANGLE 0x348F |
| |
| Accepted as values for the EGL_PLATFORM_ANGLE_TYPE_ANGLE attribute: |
| |
| EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE 0x3206 |
| |
| Accepted as values for the EGL_PLATFORM_ANGLE_DEVICE_TYPE_ANGLE attribute: |
| |
| EGL_PLATFORM_ANGLE_DEVICE_TYPE_HARDWARE_ANGLE 0x320A |
| EGL_PLATFORM_ANGLE_DEVICE_TYPE_NULL_ANGLE 0x345E |
| |
| Accepted as values for the EGL_PLATFORM_ANGLE_NATIVE_PLATFORM_TYPE_ANGLE |
| attribute: |
| |
| EGL_PLATFORM_X11_EXT 0x31D5 |
| EGL_PLATFORM_DEVICE_EXT 0x313F |
| EGL_PLATFORM_SURFACELESS_MESA 0x31DD |
| |
| Additions to the EGL Specification |
| |
| None. |
| |
| New Behavior |
| |
| To determine if the EGL implementation supports this extension, clients |
| should query the EGL_EXTENSIONS string of EGL_NO_DISPLAY. |
| |
| To obtain an EGLDisplay backed by a ANGLE display, call |
| eglGetPlatformDisplayEXT with <platform> set to EGL_PLATFORM_ANGLE_ANGLE. |
| |
| The <native_display> parameter is of type EGLNativeDisplayType. If |
| <native_display> is EGL_DEFAULT_DISPLAY a default display is returned. |
| Multiple calls with the same parameters will return the same EGLDisplay |
| handle. If <platform> is set to EGL_PLATFORM_ANGLE_ANGLE and the returned |
| display is in an uninitialized state, its attributes are overwritten by |
| those provided in the <attrib_list>, if any. |
| |
| If no <attrib_list> is specified, the value of |
| EGL_PLATFORM_ANGLE_TYPE_ANGLE is implicitly set to |
| EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE. |
| |
| If no <attrib_list> is specified, the values of |
| EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE and |
| EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE are implicitly set to |
| EGL_DONT_CARE. |
| |
| If no <attrib_list> is specified, the value of |
| EGL_PLATFORM_ANGLE_DEBUG_LAYERS_ENABLED is implicitly set to |
| EGL_DONT_CARE. |
| |
| If no <attrib_list> is specified to eglGetPlatformDisplayEXT, the value of |
| EGL_PLATFORM_ANGLE_DEVICE_TYPE_ANGLE is implicitly set to |
| EGL_PLATFORM_ANGLE_DEVICE_TYPE_HARDWARE_ANGLE. Otherwise, the value of |
| EGL_PLATFORM_ANGLE_DEVICE_TYPE_ANGLE should be: |
| - EGL_PLATFORM_ANGLE_DEVICE_TYPE_HARDWARE_ANGLE to request a hardware |
| accelerated device. |
| - EGL_PLATFORM_ANGLE_DEVICE_TYPE_NULL_ANGLE to request a no-op driver |
| for testing. If unavailable, the implementation will fall back to |
| EGL_PLATFORM_ANGLE_DEVICE_TYPE_HARDWARE_ANGLE. |
| |
| If EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE is set to EGL_DONT_CARE and |
| EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE is not set to EGL_DONT_CARE, |
| an EGL_BAD_ATTRIBUTE error is generated and EGL_NO_DISPLAY is returned. |
| |
| If no display matching the requested <native_display> or of the type |
| requested by the value of EGL_PLATFORM_ANGLE_TYPE_ANGLE is available, |
| EGL_NO_DISPLAY is returned. No error condition is raised in this case. |
| |
| If EGL_PLATFORM_ANGLE_DEBUG_LAYERS_ENABLED is specified, it |
| controls enabling back-end validation layers. EGL_TRUE enables |
| validation and EGL_FALSE disables it. If it is set to EGL_DONT_CARE, the |
| default setting depends on the implementation. Any value other than these |
| will result in an error. |
| |
| EGL_PLATFORM_ANGLE_NATIVE_PLATFORM_TYPE_ANGLE is an additional optional |
| attribute that helps ANGLE to identify what native underlaying platform |
| it should use. If no display matching the requested type of native platform |
| found, EGL_NO_DISPLAY should be returned. if no <attrib_list> is specified |
| to eglGetPlatformDisplayEXT, ANGLE is free to make the choice. |
| |
| Issues |
| |
| 1) Should the validation layers default to on, off, or no guarantee? |
| |
| Defaulting to off offers some consistency. However, it's customary for |
| some applications like ANGLE to turn on debugging features by default |
| in Debug builds. |
| |
| RESOLVED: default to implementation-dependent behaviour. |
| |
| Revision History |
| |
| Version 1, 2014-02-04 (Scott Graham) |
| - Initial draft |
| Version 2, 2014-06-05 (Geoff Lang) |
| - Rename extension from ANGLE_platform_angle_d3d to ANGLE_platform_angle. |
| - Add sub-extensions for specific platforms. |
| Version 3, 2014-10-20 (Geoff Lang) |
| - Add attributes to request specific feature level and context versions. |
| - Moved descriptions of platforms to child extension specs. |
| Version 4, 2017-07-19 (Jamie Madill) |
| - Add a debug layers enabled attribute to control runtime validation. |
| Version 5, 2017-12-28 (Jamie Madill) |
| - Expose device type selection. |
| Version 6, 2020-05-28 (Maksim Sisov) |
| - Add EGL_PLATFORM_ANGLE_NATIVE_PLATFORM_TYPE_ANGLE attribute. |
